I've been reading a very interesting book these past few days, Julian Jaynes' "The Origin of Consciousness in the Breakdown of the Bicameral Mind".
I've often thought about how we came to be as we are and read upon the subject, this book presents the best theory that I have yet seen.
According to the theory, consciousness is a late comer to the party.
Humanity's evolution of speech and reason did not need consciousness. Speech allowed far larger social groups to be coherent and reason allowed us to cope with the increased complexity of our environments.
As groups increased in size and settlements were formed, humanity needed some means of "sustaining" activities that have no immediate apparent reward.
The mechanism postulated is that of part of a brain that evolved to store the admonitions and advice given by parents and those in authority and to play it back. To a modern mind this playback would appear to be an auditory hallucination. Thus a non-conscious human could persist in preparing a field for planting despite the lack of immediate reward. A voice would be heard, possibly of a parent or of a leader continually reminding them to 'prepare the field for planting'.
Initially this mechanism would have been a simple playback mechanism, but driven by societal advances, it would have increased in complexity and would have been able to synthesise original commands.
The potential ramifications are interesting, the auditory hallucinations based on the voice of a person would have persisted long after the person had died, leading to a belief in life after death and even to worship of ancestors. As the complexity of the mechanism increased, there is no reason not to assume that the voices were limited to known people, and instead could have been interpreted as coming from gods.
It is interesting to note how much of the early writings available to us, talk about how people acted on the promptings of gods or goddesses and how there is very little about personal motivation. Indeed a case can be made that the introspection is a later addition to the text.
In effect early humanity were hallucinating schizophrenics (Bicameral) and much of the structure of ancient societies can be explained by this.
Consciousness only emerged when language gained enough complexity to support a concept of "I" and humanity was forced to evolve mentally by the breakdown of their bicameral societies. Consciousness emerged as an outcome of the integration of the hallucinatory aspects of our minds with the logical/active portions and the ability to conceptualise a self.
I've summarised very briefly here my understanding of a much more complete argument and have only touched on its consequences. I came across this theory first in fiction through the works of Neal Stepenson and other authors, now I can see where they took there inspiration.
I'm certain that this theory is not totally correct, but I would argue that it needs to be considered seriously as we continue to try to arrive at a full understanding of consciousness. It addresses for me how consciousness could arise without a significant physiological change.
The 'self' may be just a construct and this speaks interestingly for future human social and mental evolution.
